Abstract：Hypoplastic constitutive theory，which was originated from the middle and late stage of the 20th century，is a new type of soil constitutive theory based on rational mechanics. Hypoplastic theory can reflect inelasticity，nonlinearity，dilatancy and other main mechanical properties of granular material. The origin and development，general representation of hypoplastic constitutive model are introduced；and mechanical and mathematical analysis is made. Besides，the modeling thought of recently updated hypoplastic models is briefly introduced based on the study of the relation between void ratio and mean pressure and the relation between void ratio and volumetric strain of granular soil. Combining with the analysis of main mechanical properties of rockfill，the Gudehus-Bauer hypoplastic model which can reflect the latest international hypoplastic research level is modified properly and applied to constitutive modeling of rockfill. Finally，the new modified model is used in the hypoplastic numerical analysis of deformation and stress of a typical concrete face rockfill dam. Theoretical analysis and engineering application show that the new updated model can reflect inelasticity，nonlinearity，dilatancy and other main mechanical behaviors of rockfill and has the advantage of wide adaptability of constitutive parameters.
